appsec: add smoke tests for apm standalone

[florentinl]

Motivation

Test that AppSec is correctly enabled and functional in APM Standalone mode (with infra disabled at the agent level).

To do so, I setup a testing class that performs AAP smoke tests using only data intercepted at the agent level. This testing class can then be used through inheritance to create different test suites linked to different features and manifest entries.

Changes

• Add appsec helpers in interfaces.agent to perform assertions on traces intercepted after the agent
• Add smoke tests to check:
  • Threat detection
  • RASP
  • Remote configuration of rules
  • Telemetry emission
  • API Security
    => This ensures that all communication protocols used by AAP (traces, trace stats, telemetry and RC) keep getting proxied by the agent.
• Add two scenarios and a feature for APM Standalone and ASM Standalone + APM Standalone

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed and the CI green, you can merge it!

🛟 #apm-shared-testing 🛟

Reviewer checklist

• Anything but tests/ or manifests/ is modified ? I have the approval from R&P team
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added, removed or renamed?
  • Get a review from R&P team

[github-actions]

CODEOWNERS have been resolved as:

tests/appsec/test_agent_level_smoke_tests.py                            @DataDog/asm-libraries @DataDog/system-tests-core
.github/workflows/run-end-to-end.yml                                    @DataDog/system-tests-core
docs/edit/agent-interface-validation-methods.md                         @DataDog/system-tests-core
manifests/agent.yml                                                     @DataDog/system-tests-core
manifests/cpp_nginx.yml                                                 @DataDog/dd-trace-cpp
manifests/dotnet.yml                                                    @DataDog/apm-dotnet @DataDog/asm-dotnet
manifests/golang.yml                                                    @DataDog/dd-trace-go-guild
manifests/java.yml                                                      @DataDog/asm-java @DataDog/apm-java
manifests/nodejs.yml                                                    @DataDog/dd-trace-js
manifests/python.yml                                                    @DataDog/apm-python @DataDog/asm-python
manifests/ruby.yml                                                      @DataDog/ruby-guild @DataDog/asm-ruby
utils/_context/_scenarios/__init__.py                                   @DataDog/system-tests-core
utils/_features.py                                                      @DataDog/system-tests-core
utils/interfaces/_agent.py                                              @DataDog/system-tests-core